X-ray unit



Nov. 10, 1959 F. ZABRANSKY 2,9

X-RAY UNIT Filed April 25, 1957 INVENTORY FRANZ ZABRRNSKY BY MHXWELL E5PARRM ATTORNEY U wds ws P t Q 2,912,590 v X-RAY UNIT Franz Zabransky, Vienna, AuslIia Application April 23, 1957, Serial No. 654,538 Claims priority, application Austria April 26, 1956 5 Claims. 01. 250-90 In the desire to increase the output of X-ray apparatus, particularly of small-size, so-called single-tank apparatus, without increasing the weight thereof, it has always been attempted so far to achieve savings in weight by the use of higher-grade materials of construction. For instance, oils and materials having a high insulating power were used in the high-voltage transformer in order to enable a reduction in the size of the transformer. The same object is served by the use of special transformer sheets of high magnetic saturation, which enable a reduction in the size of the iron core. A special design of the transformer assembled with the X-ray tube has also enabled a light-weight construction.

However, the complete high-voltage transformer has always been accommodated in a supporting casing so far, which was rotatably held in a fork connected to the outside thereof.

It is an object of the invention to provide an X-ray unit consisting of an X-ray tube and a high-voltage transformer, particularly for a small-size X-ray apparatus, in which the transformer has plastic material molded around it and the construction of which is simplified in a previously unknown degree and distinguishes by a particularly economical expenditure of material without reducing the output of the apparatus. According to the invention the unit is characterized in that the molded plastic body of the transformer carries and preferably encloses ice tube are rotatably arranged around the primary winding 9.

The'iron core of the transformer is designed toform a rotatable holding fork. To this end the laminated core 10 maybe embraced by a clip or holder '11, to whicha trunnion 12 is affixed, which is rotatably carried in a the X-ray tube and defines at the same time the major In the accompanying drawings Fig. 1 is a side elevation and Fig. 2 a sectional view showing an illustrative embodiment of a small-size X-ray apparatus according to the invention, such as may be used, e.g., with good success in dental practice, in a design in which the self- .supporting unit is formed only by the secondary winding and the tube part.

The secondary winding 1 of the high-voltage transformer has a high-voltage insulating plastic cast around it. The resulting body 2 is here designed to form at the same time a cavity 4 for accommodating the X-ray tube 3. This cavity has a ray exit window 5 and is provided with a threaded extension 6 for screwing the various reception tubes thereon. The X-ray tube 3 may easily be exchanged after the closure caps 7 have been unscrewed.

The space between the glass wall of the X-ray tube and the plastic housing may be filled with high-grade insulatmg oil to enable a thermal expansion of the tube 3 and possibly also of the body 2 and to provide for an adequate insulation of the X-ray tube. Oil-resisting rubber suitable bracket.- This provides for the usual bearing arrangement, which enables the adjustment of the X-ray beam to any desired position in space; i Y A The body 2 consists suitably of a cast resin. These resins are cast into a mold together with a hardening agent and polymerize in the mold. Commercial casting resins are available, e.g., as ethoxiline resins.

The filled mold is suitably introduced into a vacuum container to ensure that the insulating resin will displace the air between the turns of the coil embedded therein. A self-supporting body thus obtained is absolutely stable in shape; it has excellent mechanical and electrical properties and does not require a separate surface covering. The fork 13 or the like which serves for holding the X-ray tube and as a means for leading current to the tube 3 is also embedded in the mass. The second electrical conduit for the tube is designated 14.

In order to prevent an undesired leakage of X-rays from the resulting body the material may have electrically indifferent heavy substances such as bismuth trichloride admixed thereto. Such a synthetic resin body may also be provided with a decorative or groundable conductive coating, e.g. by painting a conductive metallic coating thereon or producing a metallic coating by metallizing according to Schoops method.

If it is desired in accordance with the broader aspect of the invention to form the entire unit as a supporting structure the body 2 will enclose also the laminated core 10. The resulting body is rotatably supported in a suitable manner and is provided for this purpose with trunnions engaged by the above-mentioned rotary fork.

Instead of using a uniform synthetic resin several of such resins having different electrical and/or mechanical properties may be used to produce a laminated type of plastic body.

The construction according to the invention affords the following additional important advantages:

The substantial saving in material resulting from the use of a high-voltage insulating plastic, which serves at the same time as a supporting casing for the X-ray tube, is clearly apparent. An additional saving in material results in the construction shown in the drawing from the use of the iron core as a holding fork, whereby the weight and expenditure of material are much reduced.

This simplified construction results in an important reduction in manufacturing costs. Finally, the reduced Weight of the unit enables also a lighter and less expensive construction of the parts of the apparatus which carry the unit.

I claim:

1. An X-ray unit comprising an homogeneously molded insulating thermoplastic body block having two cavities, first and second respectively, a high-frequency transformer having an iron core, a primary winding and a secondary winding, said secondary winding of said highfrequency transformer being cast in said body block surrounding said first cavity, an X-ray tube in said second cavity, means for supporting said X-ray tube freely suspended in said second cavity, said supporting means connecting said X-ray tube electrically with said secv) ondary winding and having said iron core and said primary winding of said high-frequency transformer rotatably located in said first cavity concentric with said secondary winding of said high-frequency transformer.

2. An X-ray unit according to claim 1, and having a fork-shaped support rotatably holding said homogeneous molded insulating thermoplastic body block in said first cavity, said support comprising said iron core and said primary Winding of said high-frequency transformer.

3. An X-ray unit according to claim 1, and having an external conductive metallic coating on said insulating thermoplastic body block.

4. An X-ray unit comprising an homogeneously molded insulating thermoplastic body block having a cavity, a high-frequency transformer having an iron core, a primary winding, a secondary Winding, the secondary Winding of said high-frequency transformer permanently cast in said body block surrounding said cavity, an X-ray tube 10 of a radiation-shielding material.

References Cited in the file of this patent UNITED STATES PATENTS 15 2,118,457 Bouwers May 24, 1938 FOREIGN PATENTS 437,420 Great Britain Oct. 29, 1935 

